With the development of communication technologies, various methods for wireless communication have been used so as to overcome inconvenience of wired communication. Among those, an institute of electrical and electronic engineers (IEEE) 802.11 based wireless local area network (WLAN) has been in the limelight recently. The IEEE is a standardization organization for WLAN technologies. The IEEE 802.11 WLAN technology is increasingly popular and is becoming the dominant technology in wireless networking.
In WLAN, multiple access communication systems are used when more than two stations utilize a common medium or channel for communication with an access point (AP). There are many types of multiple access schemes and one such scheme is carrier sense multiple access (CSMA), such as CSMA with collision detection (CSMA/CD), and CSMA with collision avoidance (CSMA/CA). Generally, the CSMA scheme requires a station to use the medium to communicate in order to detect whether another station is currently using the medium. If the station detects that other station is using the medium, the station waits for the other station's communication to complete before attempting to communicate on the medium.
However, when multiple stations are waiting for other station's transmission to complete, multiple stations attempt to transmit on the medium simultaneously, upon completion of transmission. Thus leading to a collision. Due to the collision, it is possible that neither of attempts to communicate is successful. Thus, CSMA/CA has been developed as refinements of the basic CSMA concept in order to reduce the impact or avoid collisions by introducing a random amount of delay for transmission attempt over the medium.
Further, in the multiple access communication systems, transmission and reception of signals take place through a wireless medium, and a transceiver may employ an antenna for the transmission and reception. It is often desirable to use a same (i.e., common) antenna for multiple transceivers to reduce implementation area and cost. Typically reception chain (circuitry) is switched off during transmission to avoid receiving the self-transmitted signal. It may be desirable to enable a simultaneous transmission and reception (STAR) by the multiple transceivers using the same antenna. The STAR refers to transmission and reception in a same time interval. For example, assuming a scenario in which two transceivers use a same antenna, STAR means that each of the two transceivers may transmit in a same (or partially overlapping) time interval, or each of the two transceivers may receive in a same (or partially overlapping) time interval, or one of the transceivers transmits while the other receives in the same (or overlapping) time interval. Therefore, STAR allows a full duplex communication in which transmission and reception can happen simultaneously.